xref: /freebsd/sys/dev/netmap/if_ptnet.c (revision d6b92ffa)
1 /*-
2  * Copyright (c) 2016, Vincenzo Maffione
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /* Driver for ptnet paravirtualized network device. */
30 
31 #include <sys/cdefs.h>
32 
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/sockio.h>
38 #include <sys/mbuf.h>
39 #include <sys/malloc.h>
40 #include <sys/module.h>
41 #include <sys/socket.h>
42 #include <sys/sysctl.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/taskqueue.h>
46 #include <sys/smp.h>
47 #include <sys/time.h>
48 #include <machine/smp.h>
49 
50 #include <vm/uma.h>
51 #include <vm/vm.h>
52 #include <vm/pmap.h>
53 
54 #include <net/ethernet.h>
55 #include <net/if.h>
56 #include <net/if_var.h>
57 #include <net/if_arp.h>
58 #include <net/if_dl.h>
59 #include <net/if_types.h>
60 #include <net/if_media.h>
61 #include <net/if_vlan_var.h>
62 #include <net/bpf.h>
63 
64 #include <netinet/in_systm.h>
65 #include <netinet/in.h>
66 #include <netinet/ip.h>
67 #include <netinet/ip6.h>
68 #include <netinet6/ip6_var.h>
69 #include <netinet/udp.h>
70 #include <netinet/tcp.h>
71 #include <netinet/sctp.h>
72 
73 #include <machine/bus.h>
74 #include <machine/resource.h>
75 #include <sys/bus.h>
76 #include <sys/rman.h>
77 
78 #include <dev/pci/pcivar.h>
79 #include <dev/pci/pcireg.h>
80 
81 #include "opt_inet.h"
82 #include "opt_inet6.h"
83 
84 #include <sys/selinfo.h>
85 #include <net/netmap.h>
86 #include <dev/netmap/netmap_kern.h>
87 #include <net/netmap_virt.h>
88 #include <dev/netmap/netmap_mem2.h>
89 #include <dev/virtio/network/virtio_net.h>
90 
91 #ifndef PTNET_CSB_ALLOC
92 #error "No support for on-device CSB"
93 #endif
94 
95 #ifndef INET
96 #error "INET not defined, cannot support offloadings"
97 #endif
98 
99 #if __FreeBSD_version >= 1100000
100 static uint64_t	ptnet_get_counter(if_t, ift_counter);
101 #else
102 typedef struct ifnet *if_t;
103 #define if_getsoftc(_ifp)   (_ifp)->if_softc
104 #endif
105 
106 //#define PTNETMAP_STATS
107 //#define DEBUG
108 #ifdef DEBUG
109 #define DBG(x) x
110 #else   /* !DEBUG */
111 #define DBG(x)
112 #endif  /* !DEBUG */
113 
114 extern int ptnet_vnet_hdr; /* Tunable parameter */
115 
116 struct ptnet_softc;
117 
118 struct ptnet_queue_stats {
119 	uint64_t	packets; /* if_[io]packets */
120 	uint64_t	bytes;	 /* if_[io]bytes */
121 	uint64_t	errors;	 /* if_[io]errors */
122 	uint64_t	iqdrops; /* if_iqdrops */
123 	uint64_t	mcasts;  /* if_[io]mcasts */
124 #ifdef PTNETMAP_STATS
125 	uint64_t	intrs;
126 	uint64_t	kicks;
127 #endif /* PTNETMAP_STATS */
128 };
129 
130 struct ptnet_queue {
131 	struct ptnet_softc		*sc;
132 	struct				resource *irq;
133 	void				*cookie;
134 	int				kring_id;
135 	struct ptnet_ring		*ptring;
136 	unsigned int			kick;
137 	struct mtx			lock;
138 	struct buf_ring			*bufring; /* for TX queues */
139 	struct ptnet_queue_stats	stats;
140 #ifdef PTNETMAP_STATS
141 	struct ptnet_queue_stats	last_stats;
142 #endif /* PTNETMAP_STATS */
143 	struct taskqueue		*taskq;
144 	struct task			task;
145 	char				lock_name[16];
146 };
147 
148 #define PTNET_Q_LOCK(_pq)	mtx_lock(&(_pq)->lock)
149 #define PTNET_Q_TRYLOCK(_pq)	mtx_trylock(&(_pq)->lock)
150 #define PTNET_Q_UNLOCK(_pq)	mtx_unlock(&(_pq)->lock)
151 
152 struct ptnet_softc {
153 	device_t		dev;
154 	if_t			ifp;
155 	struct ifmedia		media;
156 	struct mtx		lock;
157 	char			lock_name[16];
158 	char			hwaddr[ETHER_ADDR_LEN];
159 
160 	/* Mirror of PTFEAT register. */
161 	uint32_t		ptfeatures;
162 	unsigned int		vnet_hdr_len;
163 
164 	/* PCI BARs support. */
165 	struct resource		*iomem;
166 	struct resource		*msix_mem;
167 
168 	unsigned int		num_rings;
169 	unsigned int		num_tx_rings;
170 	struct ptnet_queue	*queues;
171 	struct ptnet_queue	*rxqueues;
172 	struct ptnet_csb	*csb;
173 
174 	unsigned int		min_tx_space;
175 
176 	struct netmap_pt_guest_adapter *ptna;
177 
178 	struct callout		tick;
179 #ifdef PTNETMAP_STATS
180 	struct timeval		last_ts;
181 #endif /* PTNETMAP_STATS */
182 };
183 
184 #define PTNET_CORE_LOCK(_sc)	mtx_lock(&(_sc)->lock)
185 #define PTNET_CORE_UNLOCK(_sc)	mtx_unlock(&(_sc)->lock)
186 
187 static int	ptnet_probe(device_t);
188 static int	ptnet_attach(device_t);
189 static int	ptnet_detach(device_t);
190 static int	ptnet_suspend(device_t);
191 static int	ptnet_resume(device_t);
192 static int	ptnet_shutdown(device_t);
193 
194 static void	ptnet_init(void *opaque);
195 static int	ptnet_ioctl(if_t ifp, u_long cmd, caddr_t data);
196 static int	ptnet_init_locked(struct ptnet_softc *sc);
197 static int	ptnet_stop(struct ptnet_softc *sc);
198 static int	ptnet_transmit(if_t ifp, struct mbuf *m);
199 static int	ptnet_drain_transmit_queue(struct ptnet_queue *pq,
200 					   unsigned int budget,
201 					   bool may_resched);
202 static void	ptnet_qflush(if_t ifp);
203 static void	ptnet_tx_task(void *context, int pending);
204 
205 static int	ptnet_media_change(if_t ifp);
206 static void	ptnet_media_status(if_t ifp, struct ifmediareq *ifmr);
207 #ifdef PTNETMAP_STATS
208 static void	ptnet_tick(void *opaque);
209 #endif
210 
211 static int	ptnet_irqs_init(struct ptnet_softc *sc);
212 static void	ptnet_irqs_fini(struct ptnet_softc *sc);
213 
214 static uint32_t ptnet_nm_ptctl(if_t ifp, uint32_t cmd);
215 static int	ptnet_nm_config(struct netmap_adapter *na, unsigned *txr,
216 				unsigned *txd, unsigned *rxr, unsigned *rxd);
217 static void	ptnet_update_vnet_hdr(struct ptnet_softc *sc);
218 static int	ptnet_nm_register(struct netmap_adapter *na, int onoff);
219 static int	ptnet_nm_txsync(struct netmap_kring *kring, int flags);
220 static int	ptnet_nm_rxsync(struct netmap_kring *kring, int flags);
221 
222 static void	ptnet_tx_intr(void *opaque);
223 static void	ptnet_rx_intr(void *opaque);
224 
225 static unsigned	ptnet_rx_discard(struct netmap_kring *kring,
226 				 unsigned int head);
227 static int	ptnet_rx_eof(struct ptnet_queue *pq, unsigned int budget,
228 			     bool may_resched);
229 static void	ptnet_rx_task(void *context, int pending);
230 
231 #ifdef DEVICE_POLLING
232 static poll_handler_t ptnet_poll;
233 #endif
234 
235 static device_method_t ptnet_methods[] = {
236 	DEVMETHOD(device_probe,			ptnet_probe),
237 	DEVMETHOD(device_attach,		ptnet_attach),
238 	DEVMETHOD(device_detach,		ptnet_detach),
239 	DEVMETHOD(device_suspend,		ptnet_suspend),
240 	DEVMETHOD(device_resume,		ptnet_resume),
241 	DEVMETHOD(device_shutdown,		ptnet_shutdown),
242 	DEVMETHOD_END
243 };
244 
245 static driver_t ptnet_driver = {
246 	"ptnet",
247 	ptnet_methods,
248 	sizeof(struct ptnet_softc)
249 };
250 
251 /* We use (SI_ORDER_MIDDLE+2) here, see DEV_MODULE_ORDERED() invocation. */
252 static devclass_t ptnet_devclass;
253 DRIVER_MODULE_ORDERED(ptnet, pci, ptnet_driver, ptnet_devclass,
254 		      NULL, NULL, SI_ORDER_MIDDLE + 2);
255 
256 static int
257 ptnet_probe(device_t dev)
258 {
259 	if (pci_get_vendor(dev) != PTNETMAP_PCI_VENDOR_ID ||
260 		pci_get_device(dev) != PTNETMAP_PCI_NETIF_ID) {
261 		return (ENXIO);
262 	}
263 
264 	device_set_desc(dev, "ptnet network adapter");
265 
266 	return (BUS_PROBE_DEFAULT);
267 }
268 
269 static inline void ptnet_kick(struct ptnet_queue *pq)
270 {
271 #ifdef PTNETMAP_STATS
272 	pq->stats.kicks ++;
273 #endif /* PTNETMAP_STATS */
274 	bus_write_4(pq->sc->iomem, pq->kick, 0);
275 }
276 
277 #define PTNET_BUF_RING_SIZE	4096
278 #define PTNET_RX_BUDGET		512
279 #define PTNET_RX_BATCH		1
280 #define PTNET_TX_BUDGET		512
281 #define PTNET_TX_BATCH		64
282 #define PTNET_HDR_SIZE		sizeof(struct virtio_net_hdr_mrg_rxbuf)
283 #define PTNET_MAX_PKT_SIZE	65536
284 
285 #define PTNET_CSUM_OFFLOAD	(CSUM_TCP | CSUM_UDP | CSUM_SCTP)
286 #define PTNET_CSUM_OFFLOAD_IPV6	(CSUM_TCP_IPV6 | CSUM_UDP_IPV6 |\
287 				 CSUM_SCTP_IPV6)
288 #define PTNET_ALL_OFFLOAD	(CSUM_TSO | PTNET_CSUM_OFFLOAD |\
289 				 PTNET_CSUM_OFFLOAD_IPV6)
290 
291 static int
292 ptnet_attach(device_t dev)
293 {
294 	uint32_t ptfeatures = 0;
295 	unsigned int num_rx_rings, num_tx_rings;
296 	struct netmap_adapter na_arg;
297 	unsigned int nifp_offset;
298 	struct ptnet_softc *sc;
299 	if_t ifp;
300 	uint32_t macreg;
301 	int err, rid;
302 	int i;
303 
304 	sc = device_get_softc(dev);
305 	sc->dev = dev;
306 
307 	/* Setup PCI resources. */
308 	pci_enable_busmaster(dev);
309 
310 	rid = PCIR_BAR(PTNETMAP_IO_PCI_BAR);
311 	sc->iomem = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
312 					   RF_ACTIVE);
313 	if (sc->iomem == NULL) {
314 		device_printf(dev, "Failed to map I/O BAR\n");
315 		return (ENXIO);
316 	}
317 
318 	/* Negotiate features with the hypervisor. */
319 	if (ptnet_vnet_hdr) {
320 		ptfeatures |= PTNETMAP_F_VNET_HDR;
321 	}
322 	bus_write_4(sc->iomem, PTNET_IO_PTFEAT, ptfeatures); /* wanted */
323 	ptfeatures = bus_read_4(sc->iomem, PTNET_IO_PTFEAT); /* acked */
324 	sc->ptfeatures = ptfeatures;
325 
326 	/* Allocate CSB and carry out CSB allocation protocol (CSBBAH first,
327 	 * then CSBBAL). */
328 	sc->csb = malloc(sizeof(struct ptnet_csb), M_DEVBUF,
329 			 M_NOWAIT | M_ZERO);
330 	if (sc->csb == NULL) {
331 		device_printf(dev, "Failed to allocate CSB\n");
332 		err = ENOMEM;
333 		goto err_path;
334 	}
335 
336 	{
337 		/*
338 		 * We use uint64_t rather than vm_paddr_t since we
339 		 * need 64 bit addresses even on 32 bit platforms.
340 		 */
341 		uint64_t paddr = vtophys(sc->csb);
342 
343 		bus_write_4(sc->iomem, PTNET_IO_CSBBAH,
344 			    (paddr >> 32) & 0xffffffff);
345 		bus_write_4(sc->iomem, PTNET_IO_CSBBAL, paddr & 0xffffffff);
346 	}
347 
348 	num_tx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_RINGS);
349 	num_rx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_RINGS);
350 	sc->num_rings = num_tx_rings + num_rx_rings;
351 	sc->num_tx_rings = num_tx_rings;
352 
353 	/* Allocate and initialize per-queue data structures. */
354 	sc->queues = malloc(sizeof(struct ptnet_queue) * sc->num_rings,
355 			    M_DEVBUF, M_NOWAIT | M_ZERO);
356 	if (sc->queues == NULL) {
357 		err = ENOMEM;
358 		goto err_path;
359 	}
360 	sc->rxqueues = sc->queues + num_tx_rings;
361 
362 	for (i = 0; i < sc->num_rings; i++) {
363 		struct ptnet_queue *pq = sc->queues + i;
364 
365 		pq->sc = sc;
366 		pq->kring_id = i;
367 		pq->kick = PTNET_IO_KICK_BASE + 4 * i;
368 		pq->ptring = sc->csb->rings + i;
369 		snprintf(pq->lock_name, sizeof(pq->lock_name), "%s-%d",
370 			 device_get_nameunit(dev), i);
371 		mtx_init(&pq->lock, pq->lock_name, NULL, MTX_DEF);
372 		if (i >= num_tx_rings) {
373 			/* RX queue: fix kring_id. */
374 			pq->kring_id -= num_tx_rings;
375 		} else {
376 			/* TX queue: allocate buf_ring. */
377 			pq->bufring = buf_ring_alloc(PTNET_BUF_RING_SIZE,
378 						M_DEVBUF, M_NOWAIT, &pq->lock);
379 			if (pq->bufring == NULL) {
380 				err = ENOMEM;
381 				goto err_path;
382 			}
383 		}
384 	}
385 
386 	sc->min_tx_space = 64; /* Safe initial value. */
387 
388 	err = ptnet_irqs_init(sc);
389 	if (err) {
390 		goto err_path;
391 	}
392 
393 	/* Setup Ethernet interface. */
394 	sc->ifp = ifp = if_alloc(IFT_ETHER);
395 	if (ifp == NULL) {
396 		device_printf(dev, "Failed to allocate ifnet\n");
397 		err = ENOMEM;
398 		goto err_path;
399 	}
400 
401 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
402 	ifp->if_baudrate = IF_Gbps(10);
403 	ifp->if_softc = sc;
404 	ifp->if_flags = IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX;
405 	ifp->if_init = ptnet_init;
406 	ifp->if_ioctl = ptnet_ioctl;
407 #if __FreeBSD_version >= 1100000
408 	ifp->if_get_counter = ptnet_get_counter;
409 #endif
410 	ifp->if_transmit = ptnet_transmit;
411 	ifp->if_qflush = ptnet_qflush;
412 
413 	ifmedia_init(&sc->media, IFM_IMASK, ptnet_media_change,
414 		     ptnet_media_status);
415 	ifmedia_add(&sc->media, IFM_ETHER | IFM_10G_T | IFM_FDX, 0, NULL);
416 	ifmedia_set(&sc->media, IFM_ETHER | IFM_10G_T | IFM_FDX);
417 
418 	macreg = bus_read_4(sc->iomem, PTNET_IO_MAC_HI);
419 	sc->hwaddr[0] = (macreg >> 8) & 0xff;
420 	sc->hwaddr[1] = macreg & 0xff;
421 	macreg = bus_read_4(sc->iomem, PTNET_IO_MAC_LO);
422 	sc->hwaddr[2] = (macreg >> 24) & 0xff;
423 	sc->hwaddr[3] = (macreg >> 16) & 0xff;
424 	sc->hwaddr[4] = (macreg >> 8) & 0xff;
425 	sc->hwaddr[5] = macreg & 0xff;
426 
427 	ether_ifattach(ifp, sc->hwaddr);
428 
429 	ifp->if_hdrlen = sizeof(struct ether_vlan_header);
430 	ifp->if_capabilities |= IFCAP_JUMBO_MTU | IFCAP_VLAN_MTU;
431 
432 	if (sc->ptfeatures & PTNETMAP_F_VNET_HDR) {
433 		/* Similarly to what the vtnet driver does, we can emulate
434 		 * VLAN offloadings by inserting and removing the 802.1Q
435 		 * header during transmit and receive. We are then able
436 		 * to do checksum offloading of VLAN frames. */
437 		ifp->if_capabilities |= IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6
438 					| IFCAP_VLAN_HWCSUM
439 					| IFCAP_TSO | IFCAP_LRO
440 					| IFCAP_VLAN_HWTSO
441 					| IFCAP_VLAN_HWTAGGING;
442 	}
443 
444 	ifp->if_capenable = ifp->if_capabilities;
445 #ifdef DEVICE_POLLING
446 	/* Don't enable polling by default. */
447 	ifp->if_capabilities |= IFCAP_POLLING;
448 #endif
449 	snprintf(sc->lock_name, sizeof(sc->lock_name),
450 		 "%s", device_get_nameunit(dev));
451 	mtx_init(&sc->lock, sc->lock_name, "ptnet core lock", MTX_DEF);
452 	callout_init_mtx(&sc->tick, &sc->lock, 0);
453 
454 	/* Prepare a netmap_adapter struct instance to do netmap_attach(). */
455 	nifp_offset = bus_read_4(sc->iomem, PTNET_IO_NIFP_OFS);
456 	memset(&na_arg, 0, sizeof(na_arg));
457 	na_arg.ifp = ifp;
458 	na_arg.num_tx_desc = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_SLOTS);
459 	na_arg.num_rx_desc = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_SLOTS);
460 	na_arg.num_tx_rings = num_tx_rings;
461 	na_arg.num_rx_rings = num_rx_rings;
462 	na_arg.nm_config = ptnet_nm_config;
463 	na_arg.nm_krings_create = ptnet_nm_krings_create;
464 	na_arg.nm_krings_delete = ptnet_nm_krings_delete;
465 	na_arg.nm_dtor = ptnet_nm_dtor;
466 	na_arg.nm_register = ptnet_nm_register;
467 	na_arg.nm_txsync = ptnet_nm_txsync;
468 	na_arg.nm_rxsync = ptnet_nm_rxsync;
469 
470 	netmap_pt_guest_attach(&na_arg, sc->csb, nifp_offset,
471                                 bus_read_4(sc->iomem, PTNET_IO_HOSTMEMID));
472 
473 	/* Now a netmap adapter for this ifp has been allocated, and it
474 	 * can be accessed through NA(ifp). We also have to initialize the CSB
475 	 * pointer. */
476 	sc->ptna = (struct netmap_pt_guest_adapter *)NA(ifp);
477 
478 	/* If virtio-net header was negotiated, set the virt_hdr_len field in
479 	 * the netmap adapter, to inform users that this netmap adapter requires
480 	 * the application to deal with the headers. */
481 	ptnet_update_vnet_hdr(sc);
482 
483 	device_printf(dev, "%s() completed\n", __func__);
484 
485 	return (0);
486 
487 err_path:
488 	ptnet_detach(dev);
489 	return err;
490 }
491 
492 static int
493 ptnet_detach(device_t dev)
494 {
495 	struct ptnet_softc *sc = device_get_softc(dev);
496 	int i;
497 
498 #ifdef DEVICE_POLLING
499 	if (sc->ifp->if_capenable & IFCAP_POLLING) {
500 		ether_poll_deregister(sc->ifp);
501 	}
502 #endif
503 	callout_drain(&sc->tick);
504 
505 	if (sc->queues) {
506 		/* Drain taskqueues before calling if_detach. */
507 		for (i = 0; i < sc->num_rings; i++) {
508 			struct ptnet_queue *pq = sc->queues + i;
509 
510 			if (pq->taskq) {
511 				taskqueue_drain(pq->taskq, &pq->task);
512 			}
513 		}
514 	}
515 
516 	if (sc->ifp) {
517 		ether_ifdetach(sc->ifp);
518 
519 		/* Uninitialize netmap adapters for this device. */
520 		netmap_detach(sc->ifp);
521 
522 		ifmedia_removeall(&sc->media);
523 		if_free(sc->ifp);
524 		sc->ifp = NULL;
525 	}
526 
527 	ptnet_irqs_fini(sc);
528 
529 	if (sc->csb) {
530 		bus_write_4(sc->iomem, PTNET_IO_CSBBAH, 0);
531 		bus_write_4(sc->iomem, PTNET_IO_CSBBAL, 0);
532 		free(sc->csb, M_DEVBUF);
533 		sc->csb = NULL;
534 	}
535 
536 	if (sc->queues) {
537 		for (i = 0; i < sc->num_rings; i++) {
538 			struct ptnet_queue *pq = sc->queues + i;
539 
540 			if (mtx_initialized(&pq->lock)) {
541 				mtx_destroy(&pq->lock);
542 			}
543 			if (pq->bufring != NULL) {
544 				buf_ring_free(pq->bufring, M_DEVBUF);
545 			}
546 		}
547 		free(sc->queues, M_DEVBUF);
548 		sc->queues = NULL;
549 	}
550 
551 	if (sc->iomem) {
552 		bus_release_resource(dev, SYS_RES_IOPORT,
553 				     PCIR_BAR(PTNETMAP_IO_PCI_BAR), sc->iomem);
554 		sc->iomem = NULL;
555 	}
556 
557 	mtx_destroy(&sc->lock);
558 
559 	device_printf(dev, "%s() completed\n", __func__);
560 
561 	return (0);
562 }
563 
564 static int
565 ptnet_suspend(device_t dev)
566 {
567 	struct ptnet_softc *sc;
568 
569 	sc = device_get_softc(dev);
570 	(void)sc;
571 
572 	return (0);
573 }
574 
575 static int
576 ptnet_resume(device_t dev)
577 {
578 	struct ptnet_softc *sc;
579 
580 	sc = device_get_softc(dev);
581 	(void)sc;
582 
583 	return (0);
584 }
585 
586 static int
587 ptnet_shutdown(device_t dev)
588 {
589 	/*
590 	 * Suspend already does all of what we need to
591 	 * do here; we just never expect to be resumed.
592 	 */
593 	return (ptnet_suspend(dev));
594 }
595 
596 static int
597 ptnet_irqs_init(struct ptnet_softc *sc)
598 {
599 	int rid = PCIR_BAR(PTNETMAP_MSIX_PCI_BAR);
600 	int nvecs = sc->num_rings;
601 	device_t dev = sc->dev;
602 	int err = ENOSPC;
603 	int cpu_cur;
604 	int i;
605 
606 	if (pci_find_cap(dev, PCIY_MSIX, NULL) != 0)  {
607 		device_printf(dev, "Could not find MSI-X capability\n");
608 		return (ENXIO);
609 	}
610 
611 	sc->msix_mem = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
612 					      &rid, RF_ACTIVE);
613 	if (sc->msix_mem == NULL) {
614 		device_printf(dev, "Failed to allocate MSIX PCI BAR\n");
615 		return (ENXIO);
616 	}
617 
618 	if (pci_msix_count(dev) < nvecs) {
619 		device_printf(dev, "Not enough MSI-X vectors\n");
620 		goto err_path;
621 	}
622 
623 	err = pci_alloc_msix(dev, &nvecs);
624 	if (err) {
625 		device_printf(dev, "Failed to allocate MSI-X vectors\n");
626 		goto err_path;
627 	}
628 
629 	for (i = 0; i < nvecs; i++) {
630 		struct ptnet_queue *pq = sc->queues + i;
631 
632 		rid = i + 1;
633 		pq->irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
634 						 RF_ACTIVE);
635 		if (pq->irq == NULL) {
636 			device_printf(dev, "Failed to allocate interrupt "
637 					   "for queue #%d\n", i);
638 			err = ENOSPC;
639 			goto err_path;
640 		}
641 	}
642 
643 	cpu_cur = CPU_FIRST();
644 	for (i = 0; i < nvecs; i++) {
645 		struct ptnet_queue *pq = sc->queues + i;
646 		void (*handler)(void *) = ptnet_tx_intr;
647 
648 		if (i >= sc->num_tx_rings) {
649 			handler = ptnet_rx_intr;
650 		}
651 		err = bus_setup_intr(dev, pq->irq, INTR_TYPE_NET | INTR_MPSAFE,
652 				     NULL /* intr_filter */, handler,
653 				     pq, &pq->cookie);
654 		if (err) {
655 			device_printf(dev, "Failed to register intr handler "
656 					   "for queue #%d\n", i);
657 			goto err_path;
658 		}
659 
660 		bus_describe_intr(dev, pq->irq, pq->cookie, "q%d", i);
661 #if 0
662 		bus_bind_intr(sc->dev, pq->irq, cpu_cur);
663 #endif
664 		cpu_cur = CPU_NEXT(cpu_cur);
665 	}
666 
667 	device_printf(dev, "Allocated %d MSI-X vectors\n", nvecs);
668 
669 	cpu_cur = CPU_FIRST();
670 	for (i = 0; i < nvecs; i++) {
671 		struct ptnet_queue *pq = sc->queues + i;
672 		static void (*handler)(void *context, int pending);
673 
674 		handler = (i < sc->num_tx_rings) ? ptnet_tx_task : ptnet_rx_task;
675 
676 		TASK_INIT(&pq->task, 0, handler, pq);
677 		pq->taskq = taskqueue_create_fast("ptnet_queue", M_NOWAIT,
678 					taskqueue_thread_enqueue, &pq->taskq);
679 		taskqueue_start_threads(&pq->taskq, 1, PI_NET, "%s-pq-%d",
680 					device_get_nameunit(sc->dev), cpu_cur);
681 		cpu_cur = CPU_NEXT(cpu_cur);
682 	}
683 
684 	return 0;
685 err_path:
686 	ptnet_irqs_fini(sc);
687 	return err;
688 }
689 
690 static void
691 ptnet_irqs_fini(struct ptnet_softc *sc)
692 {
693 	device_t dev = sc->dev;
694 	int i;
695 
696 	for (i = 0; i < sc->num_rings; i++) {
697 		struct ptnet_queue *pq = sc->queues + i;
698 
699 		if (pq->taskq) {
700 			taskqueue_free(pq->taskq);
701 			pq->taskq = NULL;
702 		}
703 
704 		if (pq->cookie) {
705 			bus_teardown_intr(dev, pq->irq, pq->cookie);
706 			pq->cookie = NULL;
707 		}
708 
709 		if (pq->irq) {
710 			bus_release_resource(dev, SYS_RES_IRQ, i + 1, pq->irq);
711 			pq->irq = NULL;
712 		}
713 	}
714 
715 	if (sc->msix_mem) {
716 		pci_release_msi(dev);
717 
718 		bus_release_resource(dev, SYS_RES_MEMORY,
719 				     PCIR_BAR(PTNETMAP_MSIX_PCI_BAR),
720 				     sc->msix_mem);
721 		sc->msix_mem = NULL;
722 	}
723 }
724 
725 static void
726 ptnet_init(void *opaque)
727 {
728 	struct ptnet_softc *sc = opaque;
729 
730 	PTNET_CORE_LOCK(sc);
731 	ptnet_init_locked(sc);
732 	PTNET_CORE_UNLOCK(sc);
733 }
734 
735 static int
736 ptnet_ioctl(if_t ifp, u_long cmd, caddr_t data)
737 {
738 	struct ptnet_softc *sc = if_getsoftc(ifp);
739 	device_t dev = sc->dev;
740 	struct ifreq *ifr = (struct ifreq *)data;
741 	int mask, err = 0;
742 
743 	switch (cmd) {
744 	case SIOCSIFFLAGS:
745 		device_printf(dev, "SIOCSIFFLAGS %x\n", ifp->if_flags);
746 		PTNET_CORE_LOCK(sc);
747 		if (ifp->if_flags & IFF_UP) {
748 			/* Network stack wants the iff to be up. */
749 			err = ptnet_init_locked(sc);
750 		} else {
751 			/* Network stack wants the iff to be down. */
752 			err = ptnet_stop(sc);
753 		}
754 		/* We don't need to do nothing to support IFF_PROMISC,
755 		 * since that is managed by the backend port. */
756 		PTNET_CORE_UNLOCK(sc);
757 		break;
758 
759 	case SIOCSIFCAP:
760 		device_printf(dev, "SIOCSIFCAP %x %x\n",
761 			      ifr->ifr_reqcap, ifp->if_capenable);
762 		mask = ifr->ifr_reqcap ^ ifp->if_capenable;
763 #ifdef DEVICE_POLLING
764 		if (mask & IFCAP_POLLING) {
765 			struct ptnet_queue *pq;
766 			int i;
767 
768 			if (ifr->ifr_reqcap & IFCAP_POLLING) {
769 				err = ether_poll_register(ptnet_poll, ifp);
770 				if (err) {
771 					break;
772 				}
773 				/* Stop queues and sync with taskqueues. */
774 				ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
775 				for (i = 0; i < sc->num_rings; i++) {
776 					pq = sc-> queues + i;
777 					/* Make sure the worker sees the
778 					 * IFF_DRV_RUNNING down. */
779 					PTNET_Q_LOCK(pq);
780 					pq->ptring->guest_need_kick = 0;
781 					PTNET_Q_UNLOCK(pq);
782 					/* Wait for rescheduling to finish. */
783 					if (pq->taskq) {
784 						taskqueue_drain(pq->taskq,
785 								&pq->task);
786 					}
787 				}
788 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
789 			} else {
790 				err = ether_poll_deregister(ifp);
791 				for (i = 0; i < sc->num_rings; i++) {
792 					pq = sc-> queues + i;
793 					PTNET_Q_LOCK(pq);
794 					pq->ptring->guest_need_kick = 1;
795 					PTNET_Q_UNLOCK(pq);
796 				}
797 			}
798 		}
799 #endif  /* DEVICE_POLLING */
800 		ifp->if_capenable = ifr->ifr_reqcap;
801 		break;
802 
803 	case SIOCSIFMTU:
804 		/* We support any reasonable MTU. */
805 		if (ifr->ifr_mtu < ETHERMIN ||
806 				ifr->ifr_mtu > PTNET_MAX_PKT_SIZE) {
807 			err = EINVAL;
808 		} else {
809 			PTNET_CORE_LOCK(sc);
810 			ifp->if_mtu = ifr->ifr_mtu;
811 			PTNET_CORE_UNLOCK(sc);
812 		}
813 		break;
814 
815 	case SIOCSIFMEDIA:
816 	case SIOCGIFMEDIA:
817 		err = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
818 		break;
819 
820 	default:
821 		err = ether_ioctl(ifp, cmd, data);
822 		break;
823 	}
824 
825 	return err;
826 }
827 
828 static int
829 ptnet_init_locked(struct ptnet_softc *sc)
830 {
831 	if_t ifp = sc->ifp;
832 	struct netmap_adapter *na_dr = &sc->ptna->dr.up;
833 	struct netmap_adapter *na_nm = &sc->ptna->hwup.up;
834 	unsigned int nm_buf_size;
835 	int ret;
836 
837 	if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
838 		return 0; /* nothing to do */
839 	}
840 
841 	device_printf(sc->dev, "%s\n", __func__);
842 
843 	/* Translate offload capabilities according to if_capenable. */
844 	ifp->if_hwassist = 0;
845 	if (ifp->if_capenable & IFCAP_TXCSUM)
846 		ifp->if_hwassist |= PTNET_CSUM_OFFLOAD;
847 	if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
848 		ifp->if_hwassist |= PTNET_CSUM_OFFLOAD_IPV6;
849 	if (ifp->if_capenable & IFCAP_TSO4)
850 		ifp->if_hwassist |= CSUM_IP_TSO;
851 	if (ifp->if_capenable & IFCAP_TSO6)
852 		ifp->if_hwassist |= CSUM_IP6_TSO;
853 
854 	/*
855 	 * Prepare the interface for netmap mode access.
856 	 */
857 	netmap_update_config(na_dr);
858 
859 	ret = netmap_mem_finalize(na_dr->nm_mem, na_dr);
860 	if (ret) {
861 		device_printf(sc->dev, "netmap_mem_finalize() failed\n");
862 		return ret;
863 	}
864 
865 	if (sc->ptna->backend_regifs == 0) {
866 		ret = ptnet_nm_krings_create(na_nm);
867 		if (ret) {
868 			device_printf(sc->dev, "ptnet_nm_krings_create() "
869 					       "failed\n");
870 			goto err_mem_finalize;
871 		}
872 
873 		ret = netmap_mem_rings_create(na_dr);
874 		if (ret) {
875 			device_printf(sc->dev, "netmap_mem_rings_create() "
876 					       "failed\n");
877 			goto err_rings_create;
878 		}
879 
880 		ret = netmap_mem_get_lut(na_dr->nm_mem, &na_dr->na_lut);
881 		if (ret) {
882 			device_printf(sc->dev, "netmap_mem_get_lut() "
883 					       "failed\n");
884 			goto err_get_lut;
885 		}
886 	}
887 
888 	ret = ptnet_nm_register(na_dr, 1 /* on */);
889 	if (ret) {
890 		goto err_register;
891 	}
892 
893 	nm_buf_size = NETMAP_BUF_SIZE(na_dr);
894 
895 	KASSERT(nm_buf_size > 0, ("Invalid netmap buffer size"));
896 	sc->min_tx_space = PTNET_MAX_PKT_SIZE / nm_buf_size + 2;
897 	device_printf(sc->dev, "%s: min_tx_space = %u\n", __func__,
898 		      sc->min_tx_space);
899 #ifdef PTNETMAP_STATS
900 	callout_reset(&sc->tick, hz, ptnet_tick, sc);
901 #endif
902 
903 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
904 
905 	return 0;
906 
907 err_register:
908 	memset(&na_dr->na_lut, 0, sizeof(na_dr->na_lut));
909 err_get_lut:
910 	netmap_mem_rings_delete(na_dr);
911 err_rings_create:
912 	ptnet_nm_krings_delete(na_nm);
913 err_mem_finalize:
914 	netmap_mem_deref(na_dr->nm_mem, na_dr);
915 
916 	return ret;
917 }
918 
919 /* To be called under core lock. */
920 static int
921 ptnet_stop(struct ptnet_softc *sc)
922 {
923 	if_t ifp = sc->ifp;
924 	struct netmap_adapter *na_dr = &sc->ptna->dr.up;
925 	struct netmap_adapter *na_nm = &sc->ptna->hwup.up;
926 	int i;
927 
928 	device_printf(sc->dev, "%s\n", __func__);
929 
930 	if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
931 		return 0; /* nothing to do */
932 	}
933 
934 	/* Clear the driver-ready flag, and synchronize with all the queues,
935 	 * so that after this loop we are sure nobody is working anymore with
936 	 * the device. This scheme is taken from the vtnet driver. */
937 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
938 	callout_stop(&sc->tick);
939 	for (i = 0; i < sc->num_rings; i++) {
940 		PTNET_Q_LOCK(sc->queues + i);
941 		PTNET_Q_UNLOCK(sc->queues + i);
942 	}
943 
944 	ptnet_nm_register(na_dr, 0 /* off */);
945 
946 	if (sc->ptna->backend_regifs == 0) {
947 		netmap_mem_rings_delete(na_dr);
948 		ptnet_nm_krings_delete(na_nm);
949 	}
950 	netmap_mem_deref(na_dr->nm_mem, na_dr);
951 
952 	return 0;
953 }
954 
955 static void
956 ptnet_qflush(if_t ifp)
957 {
958 	struct ptnet_softc *sc = if_getsoftc(ifp);
959 	int i;
960 
961 	/* Flush all the bufrings and do the interface flush. */
962 	for (i = 0; i < sc->num_rings; i++) {
963 		struct ptnet_queue *pq = sc->queues + i;
964 		struct mbuf *m;
965 
966 		PTNET_Q_LOCK(pq);
967 		if (pq->bufring) {
968 			while ((m = buf_ring_dequeue_sc(pq->bufring))) {
969 				m_freem(m);
970 			}
971 		}
972 		PTNET_Q_UNLOCK(pq);
973 	}
974 
975 	if_qflush(ifp);
976 }
977 
978 static int
979 ptnet_media_change(if_t ifp)
980 {
981 	struct ptnet_softc *sc = if_getsoftc(ifp);
982 	struct ifmedia *ifm = &sc->media;
983 
984 	if (IFM_TYPE(ifm->ifm_media) != IFM_ETHER) {
985 		return EINVAL;
986 	}
987 
988 	return 0;
989 }
990 
991 #if __FreeBSD_version >= 1100000
992 static uint64_t
993 ptnet_get_counter(if_t ifp, ift_counter cnt)
994 {
995 	struct ptnet_softc *sc = if_getsoftc(ifp);
996 	struct ptnet_queue_stats stats[2];
997 	int i;
998 
999 	/* Accumulate statistics over the queues. */
1000 	memset(stats, 0, sizeof(stats));
1001 	for (i = 0; i < sc->num_rings; i++) {
1002 		struct ptnet_queue *pq = sc->queues + i;
1003 		int idx = (i < sc->num_tx_rings) ? 0 : 1;
1004 
1005 		stats[idx].packets	+= pq->stats.packets;
1006 		stats[idx].bytes	+= pq->stats.bytes;
1007 		stats[idx].errors	+= pq->stats.errors;
1008 		stats[idx].iqdrops	+= pq->stats.iqdrops;
1009 		stats[idx].mcasts	+= pq->stats.mcasts;
1010 	}
1011 
1012 	switch (cnt) {
1013 	case IFCOUNTER_IPACKETS:
1014 		return (stats[1].packets);
1015 	case IFCOUNTER_IQDROPS:
1016 		return (stats[1].iqdrops);
1017 	case IFCOUNTER_IERRORS:
1018 		return (stats[1].errors);
1019 	case IFCOUNTER_OPACKETS:
1020 		return (stats[0].packets);
1021 	case IFCOUNTER_OBYTES:
1022 		return (stats[0].bytes);
1023 	case IFCOUNTER_OMCASTS:
1024 		return (stats[0].mcasts);
1025 	default:
1026 		return (if_get_counter_default(ifp, cnt));
1027 	}
1028 }
1029 #endif
1030 
1031 
1032 #ifdef PTNETMAP_STATS
1033 /* Called under core lock. */
1034 static void
1035 ptnet_tick(void *opaque)
1036 {
1037 	struct ptnet_softc *sc = opaque;
1038 	int i;
1039 
1040 	for (i = 0; i < sc->num_rings; i++) {
1041 		struct ptnet_queue *pq = sc->queues + i;
1042 		struct ptnet_queue_stats cur = pq->stats;
1043 		struct timeval now;
1044 		unsigned int delta;
1045 
1046 		microtime(&now);
1047 		delta = now.tv_usec - sc->last_ts.tv_usec +
1048 			(now.tv_sec - sc->last_ts.tv_sec) * 1000000;
1049 		delta /= 1000; /* in milliseconds */
1050 
1051 		if (delta == 0)
1052 			continue;
1053 
1054 		device_printf(sc->dev, "#%d[%u ms]:pkts %lu, kicks %lu, "
1055 			      "intr %lu\n", i, delta,
1056 			      (cur.packets - pq->last_stats.packets),
1057 			      (cur.kicks - pq->last_stats.kicks),
1058 			      (cur.intrs - pq->last_stats.intrs));
1059 		pq->last_stats = cur;
1060 	}
1061 	microtime(&sc->last_ts);
1062 	callout_schedule(&sc->tick, hz);
1063 }
1064 #endif /* PTNETMAP_STATS */
1065 
1066 static void
1067 ptnet_media_status(if_t ifp, struct ifmediareq *ifmr)
1068 {
1069 	/* We are always active, as the backend netmap port is
1070 	 * always open in netmap mode. */
1071 	ifmr->ifm_status = IFM_AVALID | IFM_ACTIVE;
1072 	ifmr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
1073 }
1074 
1075 static uint32_t
1076 ptnet_nm_ptctl(if_t ifp, uint32_t cmd)
1077 {
1078 	struct ptnet_softc *sc = if_getsoftc(ifp);
1079 	/*
1080 	 * Write a command and read back error status,
1081 	 * with zero meaning success.
1082 	 */
1083 	bus_write_4(sc->iomem, PTNET_IO_PTCTL, cmd);
1084 	return bus_read_4(sc->iomem, PTNET_IO_PTCTL);
1085 }
1086 
1087 static int
1088 ptnet_nm_config(struct netmap_adapter *na, unsigned *txr, unsigned *txd,
1089 		unsigned *rxr, unsigned *rxd)
1090 {
1091 	struct ptnet_softc *sc = if_getsoftc(na->ifp);
1092 
1093 	*txr = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_RINGS);
1094 	*rxr = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_RINGS);
1095 	*txd = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_SLOTS);
1096 	*rxd = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_SLOTS);
1097 
1098 	device_printf(sc->dev, "txr %u, rxr %u, txd %u, rxd %u\n",
1099 		      *txr, *rxr, *txd, *rxd);
1100 
1101 	return 0;
1102 }
1103 
1104 static void
1105 ptnet_sync_from_csb(struct ptnet_softc *sc, struct netmap_adapter *na)
1106 {
1107 	int i;
1108 
1109 	/* Sync krings from the host, reading from
1110 	 * CSB. */
1111 	for (i = 0; i < sc->num_rings; i++) {
1112 		struct ptnet_ring *ptring = sc->queues[i].ptring;
1113 		struct netmap_kring *kring;
1114 
1115 		if (i < na->num_tx_rings) {
1116 			kring = na->tx_rings + i;
1117 		} else {
1118 			kring = na->rx_rings + i - na->num_tx_rings;
1119 		}
1120 		kring->rhead = kring->ring->head = ptring->head;
1121 		kring->rcur = kring->ring->cur = ptring->cur;
1122 		kring->nr_hwcur = ptring->hwcur;
1123 		kring->nr_hwtail = kring->rtail =
1124 			kring->ring->tail = ptring->hwtail;
1125 
1126 		ND("%d,%d: csb {hc %u h %u c %u ht %u}", t, i,
1127 		   ptring->hwcur, ptring->head, ptring->cur,
1128 		   ptring->hwtail);
1129 		ND("%d,%d: kring {hc %u rh %u rc %u h %u c %u ht %u rt %u t %u}",
1130 		   t, i, kring->nr_hwcur, kring->rhead, kring->rcur,
1131 		   kring->ring->head, kring->ring->cur, kring->nr_hwtail,
1132 		   kring->rtail, kring->ring->tail);
1133 	}
1134 }
1135 
1136 static void
1137 ptnet_update_vnet_hdr(struct ptnet_softc *sc)
1138 {
1139 	unsigned int wanted_hdr_len = ptnet_vnet_hdr ? PTNET_HDR_SIZE : 0;
1140 
1141 	bus_write_4(sc->iomem, PTNET_IO_VNET_HDR_LEN, wanted_hdr_len);
1142 	sc->vnet_hdr_len = bus_read_4(sc->iomem, PTNET_IO_VNET_HDR_LEN);
1143 	sc->ptna->hwup.up.virt_hdr_len = sc->vnet_hdr_len;
1144 }
1145 
1146 static int
1147 ptnet_nm_register(struct netmap_adapter *na, int onoff)
1148 {
1149 	/* device-specific */
1150 	if_t ifp = na->ifp;
1151 	struct ptnet_softc *sc = if_getsoftc(ifp);
1152 	int native = (na == &sc->ptna->hwup.up);
1153 	struct ptnet_queue *pq;
1154 	enum txrx t;
1155 	int ret = 0;
1156 	int i;
1157 
1158 	if (!onoff) {
1159 		sc->ptna->backend_regifs--;
1160 	}
1161 
1162 	/* If this is the last netmap client, guest interrupt enable flags may
1163 	 * be in arbitrary state. Since these flags are going to be used also
1164 	 * by the netdevice driver, we have to make sure to start with
1165 	 * notifications enabled. Also, schedule NAPI to flush pending packets
1166 	 * in the RX rings, since we will not receive further interrupts
1167 	 * until these will be processed. */
1168 	if (native && !onoff && na->active_fds == 0) {
1169 		D("Exit netmap mode, re-enable interrupts");
1170 		for (i = 0; i < sc->num_rings; i++) {
1171 			pq = sc->queues + i;
1172 			pq->ptring->guest_need_kick = 1;
1173 		}
1174 	}
1175 
1176 	if (onoff) {
1177 		if (sc->ptna->backend_regifs == 0) {
1178 			/* Initialize notification enable fields in the CSB. */
1179 			for (i = 0; i < sc->num_rings; i++) {
1180 				pq = sc->queues + i;
1181 				pq->ptring->host_need_kick = 1;
1182 				pq->ptring->guest_need_kick =
1183 					(!(ifp->if_capenable & IFCAP_POLLING)
1184 						&& i >= sc->num_tx_rings);
1185 			}
1186 
1187 			/* Set the virtio-net header length. */
1188 			ptnet_update_vnet_hdr(sc);
1189 
1190 			/* Make sure the host adapter passed through is ready
1191 			 * for txsync/rxsync. */
1192 			ret = ptnet_nm_ptctl(ifp, PTNETMAP_PTCTL_CREATE);
1193 			if (ret) {
1194 				return ret;
1195 			}
1196 		}
1197 
1198 		/* Sync from CSB must be done after REGIF PTCTL. Skip this
1199 		 * step only if this is a netmap client and it is not the
1200 		 * first one. */
1201 		if ((!native && sc->ptna->backend_regifs == 0) ||
1202 				(native && na->active_fds == 0)) {
1203 			ptnet_sync_from_csb(sc, na);
1204 		}
1205 
1206 		/* If not native, don't call nm_set_native_flags, since we don't want
1207 		 * to replace if_transmit method, nor set NAF_NETMAP_ON */
1208 		if (native) {
1209 			for_rx_tx(t) {
1210 				for (i = 0; i <= nma_get_nrings(na, t); i++) {
1211 					struct netmap_kring *kring = &NMR(na, t)[i];
1212 
1213 					if (nm_kring_pending_on(kring)) {
1214 						kring->nr_mode = NKR_NETMAP_ON;
1215 					}
1216 				}
1217 			}
1218 			nm_set_native_flags(na);
1219 		}
1220 
1221 	} else {
1222 		if (native) {
1223 			nm_clear_native_flags(na);
1224 			for_rx_tx(t) {
1225 				for (i = 0; i <= nma_get_nrings(na, t); i++) {
1226 					struct netmap_kring *kring = &NMR(na, t)[i];
1227 
1228 					if (nm_kring_pending_off(kring)) {
1229 						kring->nr_mode = NKR_NETMAP_OFF;
1230 					}
1231 				}
1232 			}
1233 		}
1234 
1235 		/* Sync from CSB must be done before UNREGIF PTCTL, on the last
1236 		 * netmap client. */
1237 		if (native && na->active_fds == 0) {
1238 			ptnet_sync_from_csb(sc, na);
1239 		}
1240 
1241 		if (sc->ptna->backend_regifs == 0) {
1242 			ret = ptnet_nm_ptctl(ifp, PTNETMAP_PTCTL_DELETE);
1243 		}
1244 	}
1245 
1246 	if (onoff) {
1247 		sc->ptna->backend_regifs++;
1248 	}
1249 
1250 	return ret;
1251 }
1252 
1253 static int
1254 ptnet_nm_txsync(struct netmap_kring *kring, int flags)
1255 {
1256 	struct ptnet_softc *sc = if_getsoftc(kring->na->ifp);
1257 	struct ptnet_queue *pq = sc->queues + kring->ring_id;
1258 	bool notify;
1259 
1260 	notify = netmap_pt_guest_txsync(pq->ptring, kring, flags);
1261 	if (notify) {
1262 		ptnet_kick(pq);
1263 	}
1264 
1265 	return 0;
1266 }
1267 
1268 static int
1269 ptnet_nm_rxsync(struct netmap_kring *kring, int flags)
1270 {
1271 	struct ptnet_softc *sc = if_getsoftc(kring->na->ifp);
1272 	struct ptnet_queue *pq = sc->rxqueues + kring->ring_id;
1273 	bool notify;
1274 
1275 	notify = netmap_pt_guest_rxsync(pq->ptring, kring, flags);
1276 	if (notify) {
1277 		ptnet_kick(pq);
1278 	}
1279 
1280 	return 0;
1281 }
1282 
1283 static void
1284 ptnet_tx_intr(void *opaque)
1285 {
1286 	struct ptnet_queue *pq = opaque;
1287 	struct ptnet_softc *sc = pq->sc;
1288 
1289 	DBG(device_printf(sc->dev, "Tx interrupt #%d\n", pq->kring_id));
1290 #ifdef PTNETMAP_STATS
1291 	pq->stats.intrs ++;
1292 #endif /* PTNETMAP_STATS */
1293 
1294 	if (netmap_tx_irq(sc->ifp, pq->kring_id) != NM_IRQ_PASS) {
1295 		return;
1296 	}
1297 
1298 	/* Schedule the tasqueue to flush process transmissions requests.
1299 	 * However, vtnet, if_em and if_igb just call ptnet_transmit() here,
1300 	 * at least when using MSI-X interrupts. The if_em driver, instead
1301 	 * schedule taskqueue when using legacy interrupts. */
1302 	taskqueue_enqueue(pq->taskq, &pq->task);
1303 }
1304 
1305 static void
1306 ptnet_rx_intr(void *opaque)
1307 {
1308 	struct ptnet_queue *pq = opaque;
1309 	struct ptnet_softc *sc = pq->sc;
1310 	unsigned int unused;
1311 
1312 	DBG(device_printf(sc->dev, "Rx interrupt #%d\n", pq->kring_id));
1313 #ifdef PTNETMAP_STATS
1314 	pq->stats.intrs ++;
1315 #endif /* PTNETMAP_STATS */
1316 
1317 	if (netmap_rx_irq(sc->ifp, pq->kring_id, &unused) != NM_IRQ_PASS) {
1318 		return;
1319 	}
1320 
1321 	/* Like vtnet, if_igb and if_em drivers when using MSI-X interrupts,
1322 	 * receive-side processing is executed directly in the interrupt
1323 	 * service routine. Alternatively, we may schedule the taskqueue. */
1324 	ptnet_rx_eof(pq, PTNET_RX_BUDGET, true);
1325 }
1326 
1327 /* The following offloadings-related functions are taken from the vtnet
1328  * driver, but the same functionality is required for the ptnet driver.
1329  * As a temporary solution, I copied this code from vtnet and I started
1330  * to generalize it (taking away driver-specific statistic accounting),
1331  * making as little modifications as possible.
1332  * In the future we need to share these functions between vtnet and ptnet.
1333  */
1334 static int
1335 ptnet_tx_offload_ctx(struct mbuf *m, int *etype, int *proto, int *start)
1336 {
1337 	struct ether_vlan_header *evh;
1338 	int offset;
1339 
1340 	evh = mtod(m, struct ether_vlan_header *);
1341 	if (evh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
1342 		/* BMV: We should handle nested VLAN tags too. */
1343 		*etype = ntohs(evh->evl_proto);
1344 		offset = sizeof(struct ether_vlan_header);
1345 	} else {
1346 		*etype = ntohs(evh->evl_encap_proto);
1347 		offset = sizeof(struct ether_header);
1348 	}
1349 
1350 	switch (*etype) {
1351 #if defined(INET)
1352 	case ETHERTYPE_IP: {
1353 		struct ip *ip, iphdr;
1354 		if (__predict_false(m->m_len < offset + sizeof(struct ip))) {
1355 			m_copydata(m, offset, sizeof(struct ip),
1356 			    (caddr_t) &iphdr);
1357 			ip = &iphdr;
1358 		} else
1359 			ip = (struct ip *)(m->m_data + offset);
1360 		*proto = ip->ip_p;
1361 		*start = offset + (ip->ip_hl << 2);
1362 		break;
1363 	}
1364 #endif
1365 #if defined(INET6)
1366 	case ETHERTYPE_IPV6:
1367 		*proto = -1;
1368 		*start = ip6_lasthdr(m, offset, IPPROTO_IPV6, proto);
1369 		/* Assert the network stack sent us a valid packet. */
1370 		KASSERT(*start > offset,
1371 		    ("%s: mbuf %p start %d offset %d proto %d", __func__, m,
1372 		    *start, offset, *proto));
1373 		break;
1374 #endif
1375 	default:
1376 		/* Here we should increment the tx_csum_bad_ethtype counter. */
1377 		return (EINVAL);
1378 	}
1379 
1380 	return (0);
1381 }
1382 
1383 static int
1384 ptnet_tx_offload_tso(if_t ifp, struct mbuf *m, int eth_type,
1385 		     int offset, bool allow_ecn, struct virtio_net_hdr *hdr)
1386 {
1387 	static struct timeval lastecn;
1388 	static int curecn;
1389 	struct tcphdr *tcp, tcphdr;
1390 
1391 	if (__predict_false(m->m_len < offset + sizeof(struct tcphdr))) {
1392 		m_copydata(m, offset, sizeof(struct tcphdr), (caddr_t) &tcphdr);
1393 		tcp = &tcphdr;
1394 	} else
1395 		tcp = (struct tcphdr *)(m->m_data + offset);
1396 
1397 	hdr->hdr_len = offset + (tcp->th_off << 2);
1398 	hdr->gso_size = m->m_pkthdr.tso_segsz;
1399 	hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
1400 	    VIRTIO_NET_HDR_GSO_TCPV6;
1401 
1402 	if (tcp->th_flags & TH_CWR) {
1403 		/*
1404 		 * Drop if VIRTIO_NET_F_HOST_ECN was not negotiated. In FreeBSD,
1405 		 * ECN support is not on a per-interface basis, but globally via
1406 		 * the net.inet.tcp.ecn.enable sysctl knob. The default is off.
1407 		 */
1408 		if (!allow_ecn) {
1409 			if (ppsratecheck(&lastecn, &curecn, 1))
1410 				if_printf(ifp,
1411 				    "TSO with ECN not negotiated with host\n");
1412 			return (ENOTSUP);
1413 		}
1414 		hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1415 	}
1416 
1417 	/* Here we should increment tx_tso counter. */
1418 
1419 	return (0);
1420 }
1421 
1422 static struct mbuf *
1423 ptnet_tx_offload(if_t ifp, struct mbuf *m, bool allow_ecn,
1424 		 struct virtio_net_hdr *hdr)
1425 {
1426 	int flags, etype, csum_start, proto, error;
1427 
1428 	flags = m->m_pkthdr.csum_flags;
1429 
1430 	error = ptnet_tx_offload_ctx(m, &etype, &proto, &csum_start);
1431 	if (error)
1432 		goto drop;
1433 
1434 	if ((etype == ETHERTYPE_IP && flags & PTNET_CSUM_OFFLOAD) ||
1435 	    (etype == ETHERTYPE_IPV6 && flags & PTNET_CSUM_OFFLOAD_IPV6)) {
1436 		/*
1437 		 * We could compare the IP protocol vs the CSUM_ flag too,
1438 		 * but that really should not be necessary.
1439 		 */
1440 		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
1441 		hdr->csum_start = csum_start;
1442 		hdr->csum_offset = m->m_pkthdr.csum_data;
1443 		/* Here we should increment the tx_csum counter. */
1444 	}
1445 
1446 	if (flags & CSUM_TSO) {
1447 		if (__predict_false(proto != IPPROTO_TCP)) {
1448 			/* Likely failed to correctly parse the mbuf.
1449 			 * Here we should increment the tx_tso_not_tcp
1450 			 * counter. */
1451 			goto drop;
1452 		}
1453 
1454 		KASSERT(hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM,
1455 		    ("%s: mbuf %p TSO without checksum offload %#x",
1456 		    __func__, m, flags));
1457 
1458 		error = ptnet_tx_offload_tso(ifp, m, etype, csum_start,
1459 					     allow_ecn, hdr);
1460 		if (error)
1461 			goto drop;
1462 	}
1463 
1464 	return (m);
1465 
1466 drop:
1467 	m_freem(m);
1468 	return (NULL);
1469 }
1470 
1471 static void
1472 ptnet_vlan_tag_remove(struct mbuf *m)
1473 {
1474 	struct ether_vlan_header *evh;
1475 
1476 	evh = mtod(m, struct ether_vlan_header *);
1477 	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
1478 	m->m_flags |= M_VLANTAG;
1479 
1480 	/* Strip the 802.1Q header. */
1481 	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
1482 	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
1483 	m_adj(m, ETHER_VLAN_ENCAP_LEN);
1484 }
1485 
1486 /*
1487  * Use the checksum offset in the VirtIO header to set the
1488  * correct CSUM_* flags.
1489  */
1490 static int
1491 ptnet_rx_csum_by_offset(struct mbuf *m, uint16_t eth_type, int ip_start,
1492 			struct virtio_net_hdr *hdr)
1493 {
1494 #if defined(INET) || defined(INET6)
1495 	int offset = hdr->csum_start + hdr->csum_offset;
1496 #endif
1497 
1498 	/* Only do a basic sanity check on the offset. */
1499 	switch (eth_type) {
1500 #if defined(INET)
1501 	case ETHERTYPE_IP:
1502 		if (__predict_false(offset < ip_start + sizeof(struct ip)))
1503 			return (1);
1504 		break;
1505 #endif
1506 #if defined(INET6)
1507 	case ETHERTYPE_IPV6:
1508 		if (__predict_false(offset < ip_start + sizeof(struct ip6_hdr)))
1509 			return (1);
1510 		break;
1511 #endif
1512 	default:
1513 		/* Here we should increment the rx_csum_bad_ethtype counter. */
1514 		return (1);
1515 	}
1516 
1517 	/*
1518 	 * Use the offset to determine the appropriate CSUM_* flags. This is
1519 	 * a bit dirty, but we can get by with it since the checksum offsets
1520 	 * happen to be different. We assume the host host does not do IPv4
1521 	 * header checksum offloading.
1522 	 */
1523 	switch (hdr->csum_offset) {
1524 	case offsetof(struct udphdr, uh_sum):
1525 	case offsetof(struct tcphdr, th_sum):
1526 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1527 		m->m_pkthdr.csum_data = 0xFFFF;
1528 		break;
1529 	case offsetof(struct sctphdr, checksum):
1530 		m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1531 		break;
1532 	default:
1533 		/* Here we should increment the rx_csum_bad_offset counter. */
1534 		return (1);
1535 	}
1536 
1537 	return (0);
1538 }
1539 
1540 static int
1541 ptnet_rx_csum_by_parse(struct mbuf *m, uint16_t eth_type, int ip_start,
1542 		       struct virtio_net_hdr *hdr)
1543 {
1544 	int offset, proto;
1545 
1546 	switch (eth_type) {
1547 #if defined(INET)
1548 	case ETHERTYPE_IP: {
1549 		struct ip *ip;
1550 		if (__predict_false(m->m_len < ip_start + sizeof(struct ip)))
1551 			return (1);
1552 		ip = (struct ip *)(m->m_data + ip_start);
1553 		proto = ip->ip_p;
1554 		offset = ip_start + (ip->ip_hl << 2);
1555 		break;
1556 	}
1557 #endif
1558 #if defined(INET6)
1559 	case ETHERTYPE_IPV6:
1560 		if (__predict_false(m->m_len < ip_start +
1561 		    sizeof(struct ip6_hdr)))
1562 			return (1);
1563 		offset = ip6_lasthdr(m, ip_start, IPPROTO_IPV6, &proto);
1564 		if (__predict_false(offset < 0))
1565 			return (1);
1566 		break;
1567 #endif
1568 	default:
1569 		/* Here we should increment the rx_csum_bad_ethtype counter. */
1570 		return (1);
1571 	}
1572 
1573 	switch (proto) {
1574 	case IPPROTO_TCP:
1575 		if (__predict_false(m->m_len < offset + sizeof(struct tcphdr)))
1576 			return (1);
1577 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1578 		m->m_pkthdr.csum_data = 0xFFFF;
1579 		break;
1580 	case IPPROTO_UDP:
1581 		if (__predict_false(m->m_len < offset + sizeof(struct udphdr)))
1582 			return (1);
1583 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1584 		m->m_pkthdr.csum_data = 0xFFFF;
1585 		break;
1586 	case IPPROTO_SCTP:
1587 		if (__predict_false(m->m_len < offset + sizeof(struct sctphdr)))
1588 			return (1);
1589 		m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1590 		break;
1591 	default:
1592 		/*
1593 		 * For the remaining protocols, FreeBSD does not support
1594 		 * checksum offloading, so the checksum will be recomputed.
1595 		 */
1596 #if 0
1597 		if_printf(ifp, "cksum offload of unsupported "
1598 		    "protocol eth_type=%#x proto=%d csum_start=%d "
1599 		    "csum_offset=%d\n", __func__, eth_type, proto,
1600 		    hdr->csum_start, hdr->csum_offset);
1601 #endif
1602 		break;
1603 	}
1604 
1605 	return (0);
1606 }
1607 
1608 /*
1609  * Set the appropriate CSUM_* flags. Unfortunately, the information
1610  * provided is not directly useful to us. The VirtIO header gives the
1611  * offset of the checksum, which is all Linux needs, but this is not
1612  * how FreeBSD does things. We are forced to peek inside the packet
1613  * a bit.
1614  *
1615  * It would be nice if VirtIO gave us the L4 protocol or if FreeBSD
1616  * could accept the offsets and let the stack figure it out.
1617  */
1618 static int
1619 ptnet_rx_csum(struct mbuf *m, struct virtio_net_hdr *hdr)
1620 {
1621 	struct ether_header *eh;
1622 	struct ether_vlan_header *evh;
1623 	uint16_t eth_type;
1624 	int offset, error;
1625 
1626 	eh = mtod(m, struct ether_header *);
1627 	eth_type = ntohs(eh->ether_type);
1628 	if (eth_type == ETHERTYPE_VLAN) {
1629 		/* BMV: We should handle nested VLAN tags too. */
1630 		evh = mtod(m, struct ether_vlan_header *);
1631 		eth_type = ntohs(evh->evl_proto);
1632 		offset = sizeof(struct ether_vlan_header);
1633 	} else
1634 		offset = sizeof(struct ether_header);
1635 
1636 	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1637 		error = ptnet_rx_csum_by_offset(m, eth_type, offset, hdr);
1638 	else
1639 		error = ptnet_rx_csum_by_parse(m, eth_type, offset, hdr);
1640 
1641 	return (error);
1642 }
1643 /* End of offloading-related functions to be shared with vtnet. */
1644 
1645 static inline void
1646 ptnet_sync_tail(struct ptnet_ring *ptring, struct netmap_kring *kring)
1647 {
1648 	struct netmap_ring *ring = kring->ring;
1649 
1650 	/* Update hwcur and hwtail as known by the host. */
1651         ptnetmap_guest_read_kring_csb(ptring, kring);
1652 
1653 	/* nm_sync_finalize */
1654 	ring->tail = kring->rtail = kring->nr_hwtail;
1655 }
1656 
1657 static void
1658 ptnet_ring_update(struct ptnet_queue *pq, struct netmap_kring *kring,
1659 		  unsigned int head, unsigned int sync_flags)
1660 {
1661 	struct netmap_ring *ring = kring->ring;
1662 	struct ptnet_ring *ptring = pq->ptring;
1663 
1664 	/* Some packets have been pushed to the netmap ring. We have
1665 	 * to tell the host to process the new packets, updating cur
1666 	 * and head in the CSB. */
1667 	ring->head = ring->cur = head;
1668 
1669 	/* Mimic nm_txsync_prologue/nm_rxsync_prologue. */
1670 	kring->rcur = kring->rhead = head;
1671 
1672 	ptnetmap_guest_write_kring_csb(ptring, kring->rcur, kring->rhead);
1673 
1674 	/* Kick the host if needed. */
1675 	if (NM_ACCESS_ONCE(ptring->host_need_kick)) {
1676 		ptring->sync_flags = sync_flags;
1677 		ptnet_kick(pq);
1678 	}
1679 }
1680 
1681 #define PTNET_TX_NOSPACE(_h, _k, _min)	\
1682 	((((_h) < (_k)->rtail) ? 0 : (_k)->nkr_num_slots) + \
1683 		(_k)->rtail - (_h)) < (_min)
1684 
1685 /* This function may be called by the network stack, or by
1686  * by the taskqueue thread. */
1687 static int
1688 ptnet_drain_transmit_queue(struct ptnet_queue *pq, unsigned int budget,
1689 			   bool may_resched)
1690 {
1691 	struct ptnet_softc *sc = pq->sc;
1692 	bool have_vnet_hdr = sc->vnet_hdr_len;
1693 	struct netmap_adapter *na = &sc->ptna->dr.up;
1694 	if_t ifp = sc->ifp;
1695 	unsigned int batch_count = 0;
1696 	struct ptnet_ring *ptring;
1697 	struct netmap_kring *kring;
1698 	struct netmap_ring *ring;
1699 	struct netmap_slot *slot;
1700 	unsigned int count = 0;
1701 	unsigned int minspace;
1702 	unsigned int head;
1703 	unsigned int lim;
1704 	struct mbuf *mhead;
1705 	struct mbuf *mf;
1706 	int nmbuf_bytes;
1707 	uint8_t *nmbuf;
1708 
1709 	if (!PTNET_Q_TRYLOCK(pq)) {
1710 		/* We failed to acquire the lock, schedule the taskqueue. */
1711 		RD(1, "Deferring TX work");
1712 		if (may_resched) {
1713 			taskqueue_enqueue(pq->taskq, &pq->task);
1714 		}
1715 
1716 		return 0;
1717 	}
1718 
1719 	if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
1720 		PTNET_Q_UNLOCK(pq);
1721 		RD(1, "Interface is down");
1722 		return ENETDOWN;
1723 	}
1724 
1725 	ptring = pq->ptring;
1726 	kring = na->tx_rings + pq->kring_id;
1727 	ring = kring->ring;
1728 	lim = kring->nkr_num_slots - 1;
1729 	head = ring->head;
1730 	minspace = sc->min_tx_space;
1731 
1732 	while (count < budget) {
1733 		if (PTNET_TX_NOSPACE(head, kring, minspace)) {
1734 			/* We ran out of slot, let's see if the host has
1735 			 * freed up some, by reading hwcur and hwtail from
1736 			 * the CSB. */
1737 			ptnet_sync_tail(ptring, kring);
1738 
1739 			if (PTNET_TX_NOSPACE(head, kring, minspace)) {
1740 				/* Still no slots available. Reactivate the
1741 				 * interrupts so that we can be notified
1742 				 * when some free slots are made available by
1743 				 * the host. */
1744 				ptring->guest_need_kick = 1;
1745 
1746 				/* Double-check. */
1747 				ptnet_sync_tail(ptring, kring);
1748 				if (likely(PTNET_TX_NOSPACE(head, kring,
1749 							    minspace))) {
1750 					break;
1751 				}
1752 
1753 				RD(1, "Found more slots by doublecheck");
1754 				/* More slots were freed before reactivating
1755 				 * the interrupts. */
1756 				ptring->guest_need_kick = 0;
1757 			}
1758 		}
1759 
1760 		mhead = drbr_peek(ifp, pq->bufring);
1761 		if (!mhead) {
1762 			break;
1763 		}
1764 
1765 		/* Initialize transmission state variables. */
1766 		slot = ring->slot + head;
1767 		nmbuf = NMB(na, slot);
1768 		nmbuf_bytes = 0;
1769 
1770 		/* If needed, prepare the virtio-net header at the beginning
1771 		 * of the first slot. */
1772 		if (have_vnet_hdr) {
1773 			struct virtio_net_hdr *vh =
1774 					(struct virtio_net_hdr *)nmbuf;
1775 
1776 			/* For performance, we could replace this memset() with
1777 			 * two 8-bytes-wide writes. */
1778 			memset(nmbuf, 0, PTNET_HDR_SIZE);
1779 			if (mhead->m_pkthdr.csum_flags & PTNET_ALL_OFFLOAD) {
1780 				mhead = ptnet_tx_offload(ifp, mhead, false,
1781 							 vh);
1782 				if (unlikely(!mhead)) {
1783 					/* Packet dropped because errors
1784 					 * occurred while preparing the vnet
1785 					 * header. Let's go ahead with the next
1786 					 * packet. */
1787 					pq->stats.errors ++;
1788 					drbr_advance(ifp, pq->bufring);
1789 					continue;
1790 				}
1791 			}
1792 			ND(1, "%s: [csum_flags %lX] vnet hdr: flags %x "
1793 			      "csum_start %u csum_ofs %u hdr_len = %u "
1794 			      "gso_size %u gso_type %x", __func__,
1795 			      mhead->m_pkthdr.csum_flags, vh->flags,
1796 			      vh->csum_start, vh->csum_offset, vh->hdr_len,
1797 			      vh->gso_size, vh->gso_type);
1798 
1799 			nmbuf += PTNET_HDR_SIZE;
1800 			nmbuf_bytes += PTNET_HDR_SIZE;
1801 		}
1802 
1803 		for (mf = mhead; mf; mf = mf->m_next) {
1804 			uint8_t *mdata = mf->m_data;
1805 			int mlen = mf->m_len;
1806 
1807 			for (;;) {
1808 				int copy = NETMAP_BUF_SIZE(na) - nmbuf_bytes;
1809 
1810 				if (mlen < copy) {
1811 					copy = mlen;
1812 				}
1813 				memcpy(nmbuf, mdata, copy);
1814 
1815 				mdata += copy;
1816 				mlen -= copy;
1817 				nmbuf += copy;
1818 				nmbuf_bytes += copy;
1819 
1820 				if (!mlen) {
1821 					break;
1822 				}
1823 
1824 				slot->len = nmbuf_bytes;
1825 				slot->flags = NS_MOREFRAG;
1826 
1827 				head = nm_next(head, lim);
1828 				KASSERT(head != ring->tail,
1829 					("Unexpectedly run out of TX space"));
1830 				slot = ring->slot + head;
1831 				nmbuf = NMB(na, slot);
1832 				nmbuf_bytes = 0;
1833 			}
1834 		}
1835 
1836 		/* Complete last slot and update head. */
1837 		slot->len = nmbuf_bytes;
1838 		slot->flags = 0;
1839 		head = nm_next(head, lim);
1840 
1841 		/* Consume the packet just processed. */
1842 		drbr_advance(ifp, pq->bufring);
1843 
1844 		/* Copy the packet to listeners. */
1845 		ETHER_BPF_MTAP(ifp, mhead);
1846 
1847 		pq->stats.packets ++;
1848 		pq->stats.bytes += mhead->m_pkthdr.len;
1849 		if (mhead->m_flags & M_MCAST) {
1850 			pq->stats.mcasts ++;
1851 		}
1852 
1853 		m_freem(mhead);
1854 
1855 		count ++;
1856 		if (++batch_count == PTNET_TX_BATCH) {
1857 			ptnet_ring_update(pq, kring, head, NAF_FORCE_RECLAIM);
1858 			batch_count = 0;
1859 		}
1860 	}
1861 
1862 	if (batch_count) {
1863 		ptnet_ring_update(pq, kring, head, NAF_FORCE_RECLAIM);
1864 	}
1865 
1866 	if (count >= budget && may_resched) {
1867 		DBG(RD(1, "out of budget: resched, %d mbufs pending\n",
1868 					drbr_inuse(ifp, pq->bufring)));
1869 		taskqueue_enqueue(pq->taskq, &pq->task);
1870 	}
1871 
1872 	PTNET_Q_UNLOCK(pq);
1873 
1874 	return count;
1875 }
1876 
1877 static int
1878 ptnet_transmit(if_t ifp, struct mbuf *m)
1879 {
1880 	struct ptnet_softc *sc = if_getsoftc(ifp);
1881 	struct ptnet_queue *pq;
1882 	unsigned int queue_idx;
1883 	int err;
1884 
1885 	DBG(device_printf(sc->dev, "transmit %p\n", m));
1886 
1887 	/* Insert 802.1Q header if needed. */
1888 	if (m->m_flags & M_VLANTAG) {
1889 		m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
1890 		if (m == NULL) {
1891 			return ENOBUFS;
1892 		}
1893 		m->m_flags &= ~M_VLANTAG;
1894 	}
1895 
1896 	/* Get the flow-id if available. */
1897 	queue_idx = (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) ?
1898 		    m->m_pkthdr.flowid : curcpu;
1899 
1900 	if (unlikely(queue_idx >= sc->num_tx_rings)) {
1901 		queue_idx %= sc->num_tx_rings;
1902 	}
1903 
1904 	pq = sc->queues + queue_idx;
1905 
1906 	err = drbr_enqueue(ifp, pq->bufring, m);
1907 	if (err) {
1908 		/* ENOBUFS when the bufring is full */
1909 		RD(1, "%s: drbr_enqueue() failed %d\n",
1910 			__func__, err);
1911 		pq->stats.errors ++;
1912 		return err;
1913 	}
1914 
1915 	if (ifp->if_capenable & IFCAP_POLLING) {
1916 		/* If polling is on, the transmit queues will be
1917 		 * drained by the poller. */
1918 		return 0;
1919 	}
1920 
1921 	err = ptnet_drain_transmit_queue(pq, PTNET_TX_BUDGET, true);
1922 
1923 	return (err < 0) ? err : 0;
1924 }
1925 
1926 static unsigned int
1927 ptnet_rx_discard(struct netmap_kring *kring, unsigned int head)
1928 {
1929 	struct netmap_ring *ring = kring->ring;
1930 	struct netmap_slot *slot = ring->slot + head;
1931 
1932 	for (;;) {
1933 		head = nm_next(head, kring->nkr_num_slots - 1);
1934 		if (!(slot->flags & NS_MOREFRAG) || head == ring->tail) {
1935 			break;
1936 		}
1937 		slot = ring->slot + head;
1938 	}
1939 
1940 	return head;
1941 }
1942 
1943 static inline struct mbuf *
1944 ptnet_rx_slot(struct mbuf *mtail, uint8_t *nmbuf, unsigned int nmbuf_len)
1945 {
1946 	uint8_t *mdata = mtod(mtail, uint8_t *) + mtail->m_len;
1947 
1948 	do {
1949 		unsigned int copy;
1950 
1951 		if (mtail->m_len == MCLBYTES) {
1952 			struct mbuf *mf;
1953 
1954 			mf = m_getcl(M_NOWAIT, MT_DATA, 0);
1955 			if (unlikely(!mf)) {
1956 				return NULL;
1957 			}
1958 
1959 			mtail->m_next = mf;
1960 			mtail = mf;
1961 			mdata = mtod(mtail, uint8_t *);
1962 			mtail->m_len = 0;
1963 		}
1964 
1965 		copy = MCLBYTES - mtail->m_len;
1966 		if (nmbuf_len < copy) {
1967 			copy = nmbuf_len;
1968 		}
1969 
1970 		memcpy(mdata, nmbuf, copy);
1971 
1972 		nmbuf += copy;
1973 		nmbuf_len -= copy;
1974 		mdata += copy;
1975 		mtail->m_len += copy;
1976 	} while (nmbuf_len);
1977 
1978 	return mtail;
1979 }
1980 
1981 static int
1982 ptnet_rx_eof(struct ptnet_queue *pq, unsigned int budget, bool may_resched)
1983 {
1984 	struct ptnet_softc *sc = pq->sc;
1985 	bool have_vnet_hdr = sc->vnet_hdr_len;
1986 	struct ptnet_ring *ptring = pq->ptring;
1987 	struct netmap_adapter *na = &sc->ptna->dr.up;
1988 	struct netmap_kring *kring = na->rx_rings + pq->kring_id;
1989 	struct netmap_ring *ring = kring->ring;
1990 	unsigned int const lim = kring->nkr_num_slots - 1;
1991 	unsigned int head = ring->head;
1992 	unsigned int batch_count = 0;
1993 	if_t ifp = sc->ifp;
1994 	unsigned int count = 0;
1995 
1996 	PTNET_Q_LOCK(pq);
1997 
1998 	if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
1999 		goto unlock;
2000 	}
2001 
2002 	kring->nr_kflags &= ~NKR_PENDINTR;
2003 
2004 	while (count < budget) {
2005 		unsigned int prev_head = head;
2006 		struct mbuf *mhead, *mtail;
2007 		struct virtio_net_hdr *vh;
2008 		struct netmap_slot *slot;
2009 		unsigned int nmbuf_len;
2010 		uint8_t *nmbuf;
2011 host_sync:
2012 		if (head == ring->tail) {
2013 			/* We ran out of slot, let's see if the host has
2014 			 * added some, by reading hwcur and hwtail from
2015 			 * the CSB. */
2016 			ptnet_sync_tail(ptring, kring);
2017 
2018 			if (head == ring->tail) {
2019 				/* Still no slots available. Reactivate
2020 				 * interrupts as they were disabled by the
2021 				 * host thread right before issuing the
2022 				 * last interrupt. */
2023 				ptring->guest_need_kick = 1;
2024 
2025 				/* Double-check. */
2026 				ptnet_sync_tail(ptring, kring);
2027 				if (likely(head == ring->tail)) {
2028 					break;
2029 				}
2030 				ptring->guest_need_kick = 0;
2031 			}
2032 		}
2033 
2034 		/* Initialize ring state variables, possibly grabbing the
2035 		 * virtio-net header. */
2036 		slot = ring->slot + head;
2037 		nmbuf = NMB(na, slot);
2038 		nmbuf_len = slot->len;
2039 
2040 		vh = (struct virtio_net_hdr *)nmbuf;
2041 		if (have_vnet_hdr) {
2042 			if (unlikely(nmbuf_len < PTNET_HDR_SIZE)) {
2043 				/* There is no good reason why host should
2044 				 * put the header in multiple netmap slots.
2045 				 * If this is the case, discard. */
2046 				RD(1, "Fragmented vnet-hdr: dropping");
2047 				head = ptnet_rx_discard(kring, head);
2048 				pq->stats.iqdrops ++;
2049 				goto skip;
2050 			}
2051 			ND(1, "%s: vnet hdr: flags %x csum_start %u "
2052 			      "csum_ofs %u hdr_len = %u gso_size %u "
2053 			      "gso_type %x", __func__, vh->flags,
2054 			      vh->csum_start, vh->csum_offset, vh->hdr_len,
2055 			      vh->gso_size, vh->gso_type);
2056 			nmbuf += PTNET_HDR_SIZE;
2057 			nmbuf_len -= PTNET_HDR_SIZE;
2058 		}
2059 
2060 		/* Allocate the head of a new mbuf chain.
2061 		 * We use m_getcl() to allocate an mbuf with standard cluster
2062 		 * size (MCLBYTES). In the future we could use m_getjcl()
2063 		 * to choose different sizes. */
2064 		mhead = mtail = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2065 		if (unlikely(mhead == NULL)) {
2066 			device_printf(sc->dev, "%s: failed to allocate mbuf "
2067 				      "head\n", __func__);
2068 			pq->stats.errors ++;
2069 			break;
2070 		}
2071 
2072 		/* Initialize the mbuf state variables. */
2073 		mhead->m_pkthdr.len = nmbuf_len;
2074 		mtail->m_len = 0;
2075 
2076 		/* Scan all the netmap slots containing the current packet. */
2077 		for (;;) {
2078 			DBG(device_printf(sc->dev, "%s: h %u t %u rcv frag "
2079 					  "len %u, flags %u\n", __func__,
2080 					  head, ring->tail, slot->len,
2081 					  slot->flags));
2082 
2083 			mtail = ptnet_rx_slot(mtail, nmbuf, nmbuf_len);
2084 			if (unlikely(!mtail)) {
2085 				/* Ouch. We ran out of memory while processing
2086 				 * a packet. We have to restore the previous
2087 				 * head position, free the mbuf chain, and
2088 				 * schedule the taskqueue to give the packet
2089 				 * another chance. */
2090 				device_printf(sc->dev, "%s: failed to allocate"
2091 					" mbuf frag, reset head %u --> %u\n",
2092 					__func__, head, prev_head);
2093 				head = prev_head;
2094 				m_freem(mhead);
2095 				pq->stats.errors ++;
2096 				if (may_resched) {
2097 					taskqueue_enqueue(pq->taskq,
2098 							  &pq->task);
2099 				}
2100 				goto escape;
2101 			}
2102 
2103 			/* We have to increment head irrespective of the
2104 			 * NS_MOREFRAG being set or not. */
2105 			head = nm_next(head, lim);
2106 
2107 			if (!(slot->flags & NS_MOREFRAG)) {
2108 				break;
2109 			}
2110 
2111 			if (unlikely(head == ring->tail)) {
2112 				/* The very last slot prepared by the host has
2113 				 * the NS_MOREFRAG set. Drop it and continue
2114 				 * the outer cycle (to do the double-check). */
2115 				RD(1, "Incomplete packet: dropping");
2116 				m_freem(mhead);
2117 				pq->stats.iqdrops ++;
2118 				goto host_sync;
2119 			}
2120 
2121 			slot = ring->slot + head;
2122 			nmbuf = NMB(na, slot);
2123 			nmbuf_len = slot->len;
2124 			mhead->m_pkthdr.len += nmbuf_len;
2125 		}
2126 
2127 		mhead->m_pkthdr.rcvif = ifp;
2128 		mhead->m_pkthdr.csum_flags = 0;
2129 
2130 		/* Store the queue idx in the packet header. */
2131 		mhead->m_pkthdr.flowid = pq->kring_id;
2132 		M_HASHTYPE_SET(mhead, M_HASHTYPE_OPAQUE);
2133 
2134 		if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) {
2135 			struct ether_header *eh;
2136 
2137 			eh = mtod(mhead, struct ether_header *);
2138 			if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
2139 				ptnet_vlan_tag_remove(mhead);
2140 				/*
2141 				 * With the 802.1Q header removed, update the
2142 				 * checksum starting location accordingly.
2143 				 */
2144 				if (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
2145 					vh->csum_start -= ETHER_VLAN_ENCAP_LEN;
2146 			}
2147 		}
2148 
2149 		if (have_vnet_hdr && (vh->flags & (VIRTIO_NET_HDR_F_NEEDS_CSUM
2150 					| VIRTIO_NET_HDR_F_DATA_VALID))) {
2151 			if (unlikely(ptnet_rx_csum(mhead, vh))) {
2152 				m_freem(mhead);
2153 				RD(1, "Csum offload error: dropping");
2154 				pq->stats.iqdrops ++;
2155 				goto skip;
2156 			}
2157 		}
2158 
2159 		pq->stats.packets ++;
2160 		pq->stats.bytes += mhead->m_pkthdr.len;
2161 
2162 		PTNET_Q_UNLOCK(pq);
2163 		(*ifp->if_input)(ifp, mhead);
2164 		PTNET_Q_LOCK(pq);
2165 
2166 		if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
2167 			/* The interface has gone down while we didn't
2168 			 * have the lock. Stop any processing and exit. */
2169 			goto unlock;
2170 		}
2171 skip:
2172 		count ++;
2173 		if (++batch_count == PTNET_RX_BATCH) {
2174 			/* Some packets have been pushed to the network stack.
2175 			 * We need to update the CSB to tell the host about the new
2176 			 * ring->cur and ring->head (RX buffer refill). */
2177 			ptnet_ring_update(pq, kring, head, NAF_FORCE_READ);
2178 			batch_count = 0;
2179 		}
2180 	}
2181 escape:
2182 	if (batch_count) {
2183 		ptnet_ring_update(pq, kring, head, NAF_FORCE_READ);
2184 
2185 	}
2186 
2187 	if (count >= budget && may_resched) {
2188 		/* If we ran out of budget or the double-check found new
2189 		 * slots to process, schedule the taskqueue. */
2190 		DBG(RD(1, "out of budget: resched h %u t %u\n",
2191 					head, ring->tail));
2192 		taskqueue_enqueue(pq->taskq, &pq->task);
2193 	}
2194 unlock:
2195 	PTNET_Q_UNLOCK(pq);
2196 
2197 	return count;
2198 }
2199 
2200 static void
2201 ptnet_rx_task(void *context, int pending)
2202 {
2203 	struct ptnet_queue *pq = context;
2204 
2205 	DBG(RD(1, "%s: pq #%u\n", __func__, pq->kring_id));
2206 	ptnet_rx_eof(pq, PTNET_RX_BUDGET, true);
2207 }
2208 
2209 static void
2210 ptnet_tx_task(void *context, int pending)
2211 {
2212 	struct ptnet_queue *pq = context;
2213 
2214 	DBG(RD(1, "%s: pq #%u\n", __func__, pq->kring_id));
2215 	ptnet_drain_transmit_queue(pq, PTNET_TX_BUDGET, true);
2216 }
2217 
2218 #ifdef DEVICE_POLLING
2219 /* We don't need to handle differently POLL_AND_CHECK_STATUS and
2220  * POLL_ONLY, since we don't have an Interrupt Status Register. */
2221 static int
2222 ptnet_poll(if_t ifp, enum poll_cmd cmd, int budget)
2223 {
2224 	struct ptnet_softc *sc = if_getsoftc(ifp);
2225 	unsigned int queue_budget;
2226 	unsigned int count = 0;
2227 	bool borrow = false;
2228 	int i;
2229 
2230 	KASSERT(sc->num_rings > 0, ("Found no queues in while polling ptnet"));
2231 	queue_budget = MAX(budget / sc->num_rings, 1);
2232 	RD(1, "Per-queue budget is %d", queue_budget);
2233 
2234 	while (budget) {
2235 		unsigned int rcnt = 0;
2236 
2237 		for (i = 0; i < sc->num_rings; i++) {
2238 			struct ptnet_queue *pq = sc->queues + i;
2239 
2240 			if (borrow) {
2241 				queue_budget = MIN(queue_budget, budget);
2242 				if (queue_budget == 0) {
2243 					break;
2244 				}
2245 			}
2246 
2247 			if (i < sc->num_tx_rings) {
2248 				rcnt += ptnet_drain_transmit_queue(pq,
2249 						   queue_budget, false);
2250 			} else {
2251 				rcnt += ptnet_rx_eof(pq, queue_budget,
2252 						      false);
2253 			}
2254 		}
2255 
2256 		if (!rcnt) {
2257 			/* A scan of the queues gave no result, we can
2258 			 * stop here. */
2259 			break;
2260 		}
2261 
2262 		if (rcnt > budget) {
2263 			/* This may happen when initial budget < sc->num_rings,
2264 			 * since one packet budget is given to each queue
2265 			 * anyway. Just pretend we didn't eat "so much". */
2266 			rcnt = budget;
2267 		}
2268 		count += rcnt;
2269 		budget -= rcnt;
2270 		borrow = true;
2271 	}
2272 
2273 
2274 	return count;
2275 }
2276 #endif /* DEVICE_POLLING */
2277